Synthesis And Characterization Of Polymeric Antistatic Agent-Poly(Ether Ester Amide) Containing Zinc

Polymeric antistatic agent is one of major research directions in the field of antistatic materials due to its advantages of good compatibility with matrix and stable and durable antistatic performance.In this dissertation,three kinds of polymeric antistatic agents were synthesized and studied. Firstly,poly（ether ester amide）（PEEA） and poly（ether ester amide） with MDI as chain extender（M-PEEA） were synthesized and characterized by Fourier transform infrared（FTIR） spectrum,X-ray diffraction（XRD）,differential scanning calorimetry（DSC）,scanning electron microscopy（SEM） and optical microscope（OM）.The mechanical property, hygroscopicity,dyeability and antistatic ability of PP/PEEA and PA6/M-PEEA blending fibers were also investigated.Secondly,a three-step-method process was used to synthesize hexanedioic acid,octanedioic acid or decanedioic acid based poly（ether ester amide） containing zinc（PEEAM） for the purpose of the improvement of thermal stability and antistatic effect.The structure and properties of PEEAM and its intermediate product were characterized by FTIR,XRD,DSC and thermal gravity analysis（TGA）.Moreover,the influences of PEEAM obtained from different dicarboxylic acids on the rheology,mechanical properties,hygroscopicity and antistatic ability of PA6/PEEAM fibers were studied.It was found the hexanedioic acid based PEEAM afforded an optimal antistatic effect to the blending fibers.Thirdly,to further improve the molecular weight and spinnability of hexanedioic acid based PEEAM,MDI was chosen as a chain extender to synthesize M-PEEAM,which had a rather high molecular weight and good antistatic effect.FTIR,XRD,DSC and dynamic rheometer were used to measure the structures and properties of M-PEEAM and its rmixture with polypropylene or PA6.This work also compared the antistatic effectiveness of our M-PEEAM with that of foreign antistatic agents through studying on the mechanical and antistatic properties of PA6/M-PEEAM or PP/M-PEEAM blending fibers.The main contents and results are detailed as follows:（1） Caprolactam,hexanedioic acid,and polyethylene glycol（PEG） are chosen as raw materials to synthesize PEEA in a two-step reaction.First,hexanedioic acid reacts with PEG to form poly（ether ester）（PEE）,and then PEE reacts with caprolactam to form PEEA.The chain extender of MDI is added into above reaction system to prepare the higher molecular weight PEEA（M-PEEA）.The FTIR and XRD analyses indicate that the target product is obtained.The DSC results show that the melting point of PEEA decreases and crystallization temperature increases with the PEE content,and M-PEEA has a better thermal stability compared with PEEA.The antistatic ability and hygroscopicity of PP/PEEA blending fibers increase with PEEA content or PEE content in PEEA.The blending fibers also exhibit a pretty good dyeability.The antistatic ability and hygroscopicity of PA6/M-PEEA blending fibers increase with M-PEEA content.The maximal strength of the blending fibers occurs at the MPEEA content of 6wt%.（2）Zinc oxide,hexanedioic acid（octanedioic acid or decanedioic acid）,PEG and caprolactam are chosen as raw materials to synthesize PEEAM in a three-step reaction.The esterification reaction,and structures and properties of PEEAM and its intermediate products are investigated.It is found that the esterification reaction reaches equilibrium after 3.5-4 hours.The FTIR and XRD results show that the target products of each stage are successfully prepared;the crystallinity of PEEAM decreases with PEEM content.DSC analyses indicate that the glass transition temperature and melting temperature of PEEAM decrease with the increase of PEEM content or the methylene number in dicarboxylic acid;the crystallization heat and crystallization temperature both present a minimal value with the increase of PEEM content.TGA results show that the thermal stability of PEEAM is not related much to the PEEM content and which kind of dicarboxylic acid used,however,the thermogravimetric rate increases with the increase of PEEM content.The molecular weight of PEEAM increases with the reaction time and tends to equilibrium after about 10 hours,but decreases gradually with the increase of PEEM content.（3） The synthesized PEEAM is blended with PA6.It is found that the melt flow index of the PA6/PEEAM composite increases with the PEEAM content and PEEM content in PEEAM,as well as the methylene number in dicarboxylic acid.The composites exhibit a "matrix-microfibril" structure.As the PEEA content is higher than 6wt%,a network structure constructed from microfibrils is formed in the matrix.The antistatic ability of the PA6/PEEAM fibers is improved with the increase of PEEAM content.The specific resistance of the blending fibers remains 10⁸-10⁹Ω·cm and the static half-time remains shorter than 10s after repeatedly washing.Hexanedioic acid based PA6/PEEAM blending fiber has the best antistatic performance compared with other dicarboxylic acids based PA6/PEEAM blending fibers,and it is also superior to PA6/PEEA or PA6/M-PEEA blending fibers.The retention rate of the PA6/PEEAM blending fibers increases with the PEEAM content or the PEEM content in PEEAM,but decreases with the methylene number in dicarboxylic acid.The strength of the blending fibers has a maximal value with the increase of PEEAM.（4） The chain extender of MDI is used to synthesize M-PEEAM.It is found that the addition of MDI could increase reaction rate.The FTIR analyses show the target products of each stage are successfully prepared;the molecular weight of PEG has no apparent influence on the products.The XRD pattern of M-PEEAM is different from that of PA6 or PEG, suggesting that M-PEEAM is a new product.The weakened diffraction peaks in M-PEEAM show a strong interaction between PA6 and PEEM,which restricts the crystallization of PA6 segment and PEEM segment.However,by removing the unreacted monomer,the crystallization of PA6 or PEG could be enhanced.There appears a double endothermic peak and exothermic peak in the DSC curves of M-PEEAM,showing that M-PEEAM is somewhat microphase separation.The dynamic storage modulus（G"）and loss modulus（G’）of M-PEEAM increase with the frequency（ω）,which indicates it behaves as viscous flow in the selected range ofω.The complex viscosity decreases linearly with theω,and decreases slightly with the temperature,representing a pseudoplastic fluid behavior.（5） The M-PEEAM is blended with PA6 to prepare PA6/M-PEEAM composite.It is found the melting temperature and crystallization temperature of PA6 decrease due to the existence of M-PEEAM.Nonisothermal crystallization shows that with the increase of cooling rate,the width of crystallization peak and crystallization temperature difference（ΔT_c） increase,while, the crystallization peak temperature（T_p） and half crystallization time(t_1/2) decrease,and the crystals become more imperfect.The T_p of M-PEEAM is lower than that of PA6/M-PEEAM composite under the same cooling rate.As M-PEEAM content increases,ΔT_c decreases and T_p slightly decreases,suggesting that the M-PEEAM would retard the crystallization of PA6. The crystallization behavior of PA6 in PA6/M-PEEAM composite is in accordance with Jeziorny equation.The crystallization rate constants（Z_c） increase with the cooling rate. Ozawa equation is not suitable for the description of PA6/M-PEEAM’s nonisothermal crystallization.The nonisothermal crystallization of PA-4 can be described by Mozhishen equation.The related coefficients F（T） increase with the crystallinity andαvalues vary between 1.4 and 1.59.The complex modulus（G^*）,G’ and G" of the composite increase with theω;the complex viscosity（η^*） decreases slightly with theω,indicating an obvious pseudoplastic fluid.The loss tangent（tanδ） presents a maximum with the increase ofω.In Cole-Cole curves,η" decreases with the increase ofη’ until to a minimum,then it increases and a tailing phenomenon occurs;η^* is related linearly to 1/T.In addition,the composites exhibit a "matrix-microfibril" structure.The moisture regain of the blending fibers increases with the M-PEEAM amount.Their breaking strength,specific resistance or static half-life decreases with the M-PEEAM amount.Moreover,the blending fibers have a good antistatic durability and a low dependence on ambient humidity.Comparing PA6/M-PEEAM with PA6/PEEAM,their antistatic abilities are similar,but PA6/M-PEEAM has better mechanical properties and spinnability than PA6/PEEAM.The PA6/M-PEEAM fibers’ mechanical property and antistatic ability are equivalent to or even surpass that of using foreign antistatic agents.（6） The PP/M-PEEAM composite is prepared by blending M-PEEAM and PP.The composite has a large endothermic peak at 166～167℃and two small endothermic peak at 50℃and 218℃,respectively.The appearance of multi peaks indicates that PP is incompatible with M-PEEAM.The M-PEEAM content in the composite has not much influence on the melting temperature of PP.The study on nonisothermal crystallization shows that the effect of cooling rate onΔT_c,T_p,t_1/2 is identical with the PA6/M-PEEAM system.The T_p in PP is greater than that in PP/M-PEEAM under the same cooling rate,indicating that the existence of M-PEEAM hinders the crystallization of PP.Jeziorny equation could describe the nonisothermal crystallization of PP/M-PEEAM.The G^*,G’ or G" of the composites increases with the increase ofω;η^* slightly decreases with the increase ofω,showing an obvious pseudoplastic fluid behavior;the loss tangent（tanδ） presents a maximum with the increase ofω.In Cole-Cole curves,η" decreases with the increase ofη’ until to a minimum,then it increases a little,and a tailing phenomenon occurs;η^* is related linearly to 1/T.In addition, the composites exhibit a two-phase structure.The moisture regain of the PP/M-PEEAM blending fibers increases with the M-PEEAM amount.Their breaking strength,specific resistance or static half-life decreases with the M-PEEAM amount.The PP/M-PEEAM fibers’ mechanical property and antistatic ability are equivalent to or even surpass that of using foreign antistatic agents.